Mechanism that Continuously Adjusts a Drum Position

ABSTRACT

In one aspect of the invention, a degradation machine comprises motorized vehicle supported by a plurality of translation elements. A rotary degradation drum is attached to the vehicle. At least one device provides a subsurface boundary profile. An adjustment mechanism continuously adjusts a drum position to maintain a distance of the drum from the subsurface boundary profile.

BACKGROUND OF THE INVENTION

The present invention relates to an adjustment mechanism for adjusting the position of an adjustable machining tool, such as a drum, in a degradation machine.

Examples of prior art height adjustment mechanism for milling drums are disclosed in U.S. Pat. No. 3,767,264 to Eckey, U.S. Pat. No. 4,103,973 to Cutler, U.S. Pat. No. 4,961,173 to Sehr which are all herein incorporated by reference for all that they contain.

BRIEF SUMMARY OF THE INVENTION

In one aspect of the invention, a degradation machine comprises motorized vehicle supported by a plurality of translation elements. A rotary degradation drum is attached to the vehicle. At least one device provides a subsurface boundary profile. An adjustment mechanism continuously adjusts a drum position to maintain a distance of the drum from the subsurface boundary profile.

The adjustment mechanism may comprise an adjustment arm that is in mechanical communication with an axle of the drum. The adjustment arm may comprise multiple layers of piezoelectric material. The adjustment arm may comprise multiple layers of magnetostrictive material. The adjustment arm may comprise multiple layers of electrostrictive material, conducting polymers, dielectric elastomers, or combinations thereof. The adjustment arm may comprise a linear screw actuator. The adjustment arm may comprise a hydraulic system comprising a piston connected to the axle of the drum.

The machine may be a mining machine or a road milling machine. The axle of the drum may be substantially normal to an underside of the machine. The axle of the drum may be substantially perpendicular to an underside of the machine. The at least one device may be a ground penetrating radar. The at least one device may be a GPS mounted on the machine. The at least one device may be a remote database with the subsurface boundary knowledge. The at least one device may be an acoustic sensor mounted in front of the machine.

In another aspect of the invention, a method of continuously adjusting a rotary degradation drum position of a motorized vehicle comprises the steps of providing a degradation drum attached to a degradation machine, determining a subsurface boundary profile and continuously adjusting the depth of cut to maintain a distance of the drum from the subsurface boundary profile by adjusting mechanism.

The subsurface boundary may be a boundary of a coal or mineral seam. The subsurface boundary may be a boundary between layers of pavement. Torque applied to the drum may continuously change with respect to the depth of cut. The adjustment mechanism may adjust the position of the drum to maintain a distance above the reference, below the reference or combinations thereof. The adjustment mechanism may adjust the position of the drum horizontally, vertically, or combinations thereof. The subsurface boundary profile collected by the at least one device may be communicated to the adjustment mechanism via a control unit. The adjustment mechanism may comprise a hydraulic accumulator controlled by the control unit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 a is a diagram of an embodiment of a degradation machine.

FIG. 1 b is a prior art diagram of a milling procedure.

FIG. 2 is a cross-sectional diagram of another embodiment of a degradation drum engaged with a road surface.

FIG. 3 is a perspective diagram of an embodiment of an adjustment mechanism.

FIG. 4 is a perspective diagram of another embodiment of an adjustment mechanism.

FIG. 5 is a perspective diagram of another embodiment of an adjustment mechanism.

FIG. 6 is a cross-sectional diagram of another embodiment of an adjustment mechanism.

FIG. 7 is a perspective diagram of another embodiment of an adjustment mechanism.

FIG. 8 is a schematic diagram of another embodiment of an adjustment mechanism.

FIG. 9 is an orthogonal diagram of an embodiment of a coal excavator.

DETAILED DESCRIPTION OF THE INVENTION AND THE PREFERRED EMBODIMENT

FIG. 1 a is a cross-sectional diagram that shows a plurality of degradation assemblies 101 attached to a driving mechanism 102, such as a rotatable drum attached to the underside of a pavement milling machine 103. The milling machine 103 may be a planer used to degrade man-made formations 104 such as pavement prior to placement of a new layer of pavement. The degradation assemblies 101 may be attached to the drum 102, bringing the degradation assemblies 101 into engagement with the formation 104. A holder, such as a block welded or bolted to the drum, is attached to the driving mechanism 102 and the degradation assembly is inserted into the holder. The holder may hold the degradation assembly 101 at an angle offset from the direction of rotation, such that the degradation assembly engages the formation 104 at a preferential angle. The arrow 105 shows the machine's direction of travel.

FIG. 1 b discloses a prior art milling procedure of a road surface structure. In the prior art, the depth of cut is controlled by using the top surface layer 120 as a reference layer. For example, a contractor will is hired to take an inch off the top of a paved surface. However, as shown in FIG. 1 b, the target layers may have a uniform thickness. Often, the contractor is unaware that the target layers are not uniform, and risks cutting into undesirable sublayers. Unintentionally, milling into sublayers may be damaging when the milling drum is not perfected to drilling into a layer of those characteristics.

For example, roads originally made of cement slabs are often covered with a layer of asphalt after the cement slabs have shifted over time. The shifted slabs cause the asphalt layer 130 to have a non-uniform thickness that is unknown to the contractor. Cement is much harder than asphalt. Often, if a contractor mills into the cement slabs at the same speed and toque as the when milling the asphalt, the contractor's milling equipment may risk serious damage. The cement slabs 140 may shift from their original position horizontally, vertically, angularly, or combinations thereof. The degradation assemblies 101 may follow at a uniform depth of cut as it proceeds forward as illustrated by the dashed lines 150 in the figure.

FIG. 2 discloses detailed views of degrading a road surface and sensing a location of a subsurface boundary. A sensing device 210 may comprise a sensor such as acoustic, sound, vibration, laser, position sensor, subatomic particles, GPR or GPS. The sensor 210 may transmit the impulse 200 vertically or at an angle. The reflected impulse 200 is collected by a receiver in the sensor. The GPR system may comprise an antenna unit, signal control console, display monitor and/or graphic recorder. The antenna unit may be in electrical communication with vehicle-mounted equipment.

In some embodiments, electromagnetic impulses of UHF and/or VHF frequency may be emitted from the moving antenna and propagated into the ground. Impulses 200 may be reflected at subsurface boundaries 160 where density changes. Reflected impulses may be detected by the antenna receiver and digitally stored for data processing and interpretation. The GPR method may be non-destructive, revealing subsurface detail without requiring coring, breaking out or other destructive actions. The information collected by the device 210 may be fed to an adjustment mechanism via a control unit.

In other embodiments, the road may be scanned before milling and a subsurface boundary location along the road may be stored off site. The milling machine may be in wireless/remote communication with a database containing information about the subsurface boundary as the machine mills. In such embodiments, the machine may be equipped with a location device, such as a global positioning system unit that is adapted to communicate with satellites to identify its location. Thus, the machines may integrate its knowledge of changing location and the databases subsurface boundary profile as the machine moves. In some embodiments, the database may be stored directly on the machine.

The adjustment mechanism may continuously adjust the position of the drum 102 to maintain a distance of the drum 102 from the subsurface boundary profile. As opposed to the prior art, where the depth of cut is maintained from the top surface, the present invention uses the subsurface boundary as the reference for positioning the drum. The drum may be positioned at a uniform distance above or below the subsurface boundary profile, or in some embodiments, the contractor may desire to cut along the boundary.

The adjustment mechanism may raise the position of the drum 102 to maintain its distance from the subsurface boundary between the asphalt 130 and cement slabs 140 as illustrated in FIG. 2. However, the boundary could be between layers of asphalt, layers of cement, road bases, buried objects, or combinations thereof.

The degradation assemblies 101 may penetrate deeper into the formation while adjusting its distance from the subsurface boundary 160. In some embodiments, the degradation assemblies 101 may experience more resistance as it goes deeper into the formation. High resistive forces may cause failure of the degradation assemblies 101. To avoid such failure, the adjustment mechanism continuously changes torque applied to the degradation assemblies 101 with respect to the depth of cut.

In the prior art, the milling drum's height, which determines the depth of cut, is generally adjusted periodically by adjusting hydraulic cylinders position above the tracks of the machine.

FIG. 3 is a perspective diagram of an embodiment of an adjustment mechanism adapted to adjust the milling drums height while milling. The adjustment mechanism may comprise a rotary degradation drum 102 and an adjustment arm 300 on each side of the degradation drum 102. The adjustment arm 300 may be connected to an axle of the degradation drum 102. The axle of the drum 102 may be substantially parallel to the underside of the machine 103. The adjustment arm 300 may further comprise multiple layers of piezoelectric material 310. The piezoelectric material 310 may comprise lead zirconate titanate crystals, quartz, berlinite, topaz, gallium orthophosphate, polyvinylidine fluoride, or combinations thereof. Current may be supplied through wires 320 to the layers of piezoelectric material 310 via a control unit 330 that regulates the amount of current supply. The expansion and contraction of the piezoelectric material 310 may result in the expansion and contraction of the adjustment arm 300. The expansion and contraction of the adjustment arm 300 may move the axle of the degradation drum 102, thereby moving the degradation assemblies 101 vertically up and down. The extent of the movement of the degradation assemblies 101 may depend on the amount of current supplied, the type of piezoelectric material 310, or combinations thereof.

In some embodiments, the adjustments in the drum's position may only need to span within a few inches. Thus, the adjustment mechanism may be designed for small, but precise, adjustments. Preferably, the adjustments mechanism responds instantaneously to follow the subsurface boundary's profile precisely.

FIG. 4 discloses an adjustment arm 300 on each side of the degradation drum 102 that comprises multiple layers of magnetostrictive material 400. The magnetostrictive material 400 may comprise cobalt, terfenol-D, ferromagnetic materials, or combinations. The adjustment arm 300 may further comprise coil of wire 320 wrapped around these layers. A magnetic field is produced when current is supplied through the coil of wire 320 to may expand the layers. The movement of the degradation assemblies 101 may depend on the strength of the magnetic field produced, the type of magnetostrictive material 400, or combinations thereof. The adjustment arm 300 may further comprise multiple layers of electrostrictive material, conducting polymers, dielectric elastomers, or combinations thereof.

Referring now to FIG. 5, the adjustment mechanism comprises adjustment arms 500 with linear screw translators 510 that are actuated by a motor 520. The motor 520 may be connected to a control unit 330 that regulates its rotation. The rotation of the screw may move the adjustment arm 300 vertically up or down. The movement of the degradation assemblies 101 may depend on the rotation of the motor 520, pitch of the threads on the screw, diameter of the screw, amount of current supplied, or combination thereof.

FIG. 6 discloses the drum in an angled position which may be accomplished when one of the adjustment arms 300 is extended a greater distance than the other one. Any one of the above described methods may be used to activate the adjusting arm 300. Angling the drum may aid in following various subsurface boundary profiles, especially in embodiments where cement slabs have shifted diagonally with respect to the drum's length.

FIG. 7 discloses a hydraulic system 700 comprising a piston 710 connected to the axle 720 of the drum 102. The hydraulic system 700 may comprise a reservoir 730, a plurality of pistons 710, a plurality of pumps 740 and valves 750. The opening and closing of valves 750 is controlled by a control unit 760. The movement of the drum 102 may be controlled by the combination of movement of pistons 710 in the cylinders 770, 780. The vertical downward movement of the drum 102 may be controlled by the downward movement of the piston 710 in cylinder 770. The vertical upward movement of the drum 102 may be controlled by the upward movement of the piston 710 in cylinder 780. The hydraulic system 700 may allow the drum 102 to move freely in any direction by properly coordinating the pistons' movement.

FIG. 8 discloses a schematic diagram of a hydraulic system 800 for adjusting the drum's position with the hydraulic cylinders associated with the tracks. The system 880 comprises pumps 880 and hydraulic accumulators 810. The hydraulic accumulators 810 may be connected to the main flow of the hydraulic system 800 instead of large hydraulic pumps, so that a supply circuit may respond more quickly to any temporary demand and to smooth pulsations. The hydraulic accumulator 810 may be controlled through valves 820 controlled via a control unit 830. The hydraulic system 800 may comprise cylinder 850 associated with the tracks. The hydraulic accumulators 810 are adapted to continuously make adjustments.

FIG. 9 is an diagram of an embodiment of a mining machine 900 which may incorporate the features of the present invention. The rotating drum 910 may be connected to an arms 950 that position the drum 910 in any orientation to follow a profile of a coal 920 or mineral vane . The adjustment arm 950 may incorporated in a hydraulic arm 980. The coal excavator 900 may move about by tracks, wheels, or a combination thereof.

Whereas the present invention has been described in particular relation to the drawings attached hereto, it should be understood that other and further modifications apart from those shown or suggested herein, may be made within the scope and spirit of the present invention. 

1. A degradation machine, comprising: a motorized vehicle supported by a plurality of translation elements; a rotary degradation drum attached to the vehicle; at least one device that provides a subsurface boundary profile, and an adjustment mechanism that continuously adjusts a drum position to maintain a distance of the drum from the subsurface boundary profile.
 2. The machine of claim 1, wherein the adjustment mechanism comprises an adjustment arm that is in communication with an axle of the drum.
 3. The machine of claim 2, wherein the adjustment arm comprises multiple layers of piezoelectric material.
 4. The machine of claim 2, wherein the adjustment arm comprises multiple layers of magnetostrictive material.
 5. The machine of claim 2, wherein the adjustment arm comprises multiple layers of electrostrictive material, conducting polymers, dielectric elastomers, or combinations thereof.
 6. The machine of claim 2, wherein the adjustment arm comprises a linear screw actuator.
 7. The machine of claim 2, wherein the adjustment arm comprises a hydraulic system comprising a piston connected to the axle of the drum.
 8. The machine of claim 1, wherein the machine is a road milling machine.
 9. The machine of claim 1, wherein the machine is mining machine.
 10. The machine of claim 1, wherein an axle of the drum is substantially normal to an underside of the machine.
 11. The machine of claim 1, wherein an axle of the drum is substantially parallel to an underside of the machine.
 12. The machine of claim 1, wherein the at least one device is a ground penetrating radar.
 13. The machine of claim 1, wherein the at least one device is a GPS mounted on the machine.
 14. The machine of claim 1, wherein the at least one device is a remote database with the subsurface boundary knowledge.
 15. The machine of claim 1, wherein the at least one device is an acoustic sensor mounted in front of the machine.
 16. A method of continuously adjusting a rotary degradation drum position of a motorized vehicle comprising the steps of: providing a degradation drum attached to a degradation machine; determining a subsurface boundary profile; and continuously adjusting the depth of cut to maintain a distance of the drum from the subsurface boundary profile by an adjustment mechanism.
 17. The machine of claim 16, wherein the subsurface boundary is a boundary of a coal or mineral seam.
 18. The machine of claim 16, wherein the subsurface boundary is a boundary between layers of pavement.
 19. The machine of claim 16, wherein torque applied to the drum continuously changes with respect to the depth of cut.
 20. The machine of claim 16, wherein the adjustment mechanism adjusts the position of the drum to maintain a distance above the reference, below the reference or combinations thereof. 